Childhood Vaccination Research Articles

Impact of COVID-19 lockdown measures on mother and child health - the case of Ghana.

The lockdown measures in response to the coronavirus disease (COVID-19) have led to a wide range of unintended consequences for women and children. Until the outbreak of COVID-19, attention was on reducing maternal and infant mortality due to pregnancy and delivery complications. The aim of this study was to interrogate the impact of lockdown measures on women and children in two contrasting districts in Ghana - Krobo Odumase and Ayawaso West Wuogon. This study adopted the mixed-method approach using both qualitative and quantitative data. The qualitative study relied on two data collection methods to explore the impacts of COVID-19 control measures on women and children in Ghana. These were: Focus Group Discussions (FGDs; n = 12) and Key Informant Interviews (KIIs; n = 18). The study complemented the qualitative data with survey data - household surveys (n = 78) which were used to support the nutrition and school closure data; and policy data gathered from government websites consisting of government responses to COVID-19. The qualitative data was analysed using the thematic approach with codes generated apriori with the NVIVO software. The quantitative data used percentages and frequencies. Engagements with participants in the study revealed that the lockdown measures implemented in Ghana had consequences on child and maternal health, and the health care system as a whole. Our study revealed, for example, that there was a decrease in antenatal and postnatal attendance in hospitals. Childhood vaccinations also came to a halt. Obesity and malnutrition were found to be common among children depending on the location of our study participants (urban and rural areas respectively). Our study also revealed that TB, Malaria and HIV treatment seeking reduced due to the fear of going to health facilities since those ailments manifest similar symptoms as COVID 19. Government responded to COVID-19 using different strategies however the policy response resulted in both intended and unintended consequences especially for women and children in Ghana. It is recommended that national policy directions should ensure the continuous provision of child and maternal healthcare services which are essential health services during lockdowns.

Barriers and facilitators to routine revaccination among adult Hematopoietic Cell Transplant survivors in the United States: A convergent mixed methods analysis.

Hematopoietic cell transplant (HCT) survivorship care includes recommendations for post-HCT revaccination to restore immunity to vaccine-preventable diseases (VPDs). However, not all survivors agree to be vaccinated. No existing studies have comprehensively reported barriers and facilitators to adult HCT survivors completing revaccination. A cross-sectional survey of 194 adult HCT survivors was analyzed using convergent mixed methods. The analysis used various statistical methods to determine the prevalence of barriers and facilitators and the association between revaccination and the number and specific type of barriers and facilitators. Content analysis was applied to open-ended item responses. Integrated analysis merged quantitative and qualitative findings. The most frequent barriers included the inability to receive live vaccines because of immunosuppression, identifying a suitable community location for administering childhood vaccines to adults, and delayed immune recovery. The most frequent facilitators were having healthcare insurance and a clear calendar of the revaccination schedule. Complete revaccination rates were lower with each additional reported barrier (OR = 0.58; 95% CI 0.459-0.722) and higher with each additional reported facilitator (OR = 1.31; 95% CI 1.05-1.63). Content analysis suggested that most barriers were practical issues. One significant facilitator highlighted by respondents was for the transplant center to coordinate and serve as the vaccination location for revaccination services. Merged analysis indicated convergence between quantitative and qualitative data. Practical barriers and facilitators played a consequential role in revaccination uptake, and survivors would like to be revaccinated at the transplant center.

Trends of Diphtheria–Tetanus–Pertussis and Measles Vaccine Coverage Preceding and during the COVID-19 Pandemic: An Analysis of the WHO European Region from 2000 to 2022

Available data highlights the significant impact of the COVID-19 pandemic on global vaccination trends. Despite this, comprehensive evaluations of these changes at the European level are still scarce. This study examines coverage for diphtheria, tetanus, and pertussis (DTP) and measles-containing vaccines (MCV) in the WHO European Region from 2000 to 2022. Vaccination coverage data, defined as the percentage of surviving infants who received the first and third doses of DTP (DTP1 and DTP3) and the first and second doses of MCV (MCV1 and MCV2), were extracted from UNICEF databases. Joinpoint regression analysis was employed to identify joinpoints in the time series and to estimate Annual Percent Changes (APCs) and Average Annual Percent Changes (AAPCs) over predefined timeframes. The coverages for DTP1 and MCV1 exhibit a similar trend, overall characterized by four joinpoints, one of which is in 2019. In contrast, the coverage for DTP3 does not show a significant temporal trend and lacks joinpoints, while the vaccination coverage for MCV2 shows a steadily increasing trend, with three identified joinpoints. A comparative analysis with the pre-pandemic period reveals a significant increase in the number of countries characterized by a decreasing trend during the pandemic period for all considered vaccination coverages, as indicated by the negative AAPC values. These results highlight the effect of the pandemic on childhood vaccination coverage. Compared to a mere descriptive analysis, the temporal analysis of trends using joinpoint regression provides significant opportunities to identify variations in vaccination coverages and pinpoint areas for intervention in future vaccination strategies.

Factors Associated with Parents' COVID-19 Vaccination Decisions for Their Children in an Economically Marginalized, Diverse Community.

COVID-19 vaccine hesitancy is a significant public health concern, particularly among parents who serve as gatekeepers for their child(ren)'s vaccination status. This study adds to the literature by examining COVID-19 vaccine decisions among parents living in a mid-size, lower-income, racially/ethnically diverse, community. Parents of children, < 18 years and enrolled in the public schools system, were invited to complete a questionnaire offered in English, Spanish, and Portuguese. The questionnaire included questions about their child(ren)'s vaccination status, as well as factors which, based on the literature, might impact parents' vaccination decisions. Parents (n = 277) were mostly Hispanic/Latinx, females, with a high school degree/GED as their highest level of education achieved, a mean age of 40 years, and an average of two children < 18 years. Four-fifths (78.6%) of parents reported being vaccinated against COVID-19, but only 40.8% reported having all of their children vaccinated; 14.8% had some of their children get the COVID-19 vaccine, and 44.4% had none of their children get the COVID-19 vaccine. In bivariate associations, parents' vaccination status, parents age, the CDC website as a COVID-19 information source, awareness of age eligibility for the COVID-19 vaccine, parents reporting knowing someone who does not want to vaccinate their child, and parents' perceived social norm score were associated with children's vaccination status. However, when multivariate analyses were conducted, only parents' age and perceived social norms increased parents' odds of choosing to vaccinate their child. These findings have implications for those promoting COVID-19 vaccination among parents in lower-income, diverse communities.

Impact of Conflit on Children Vaccination: Evidence from Central North, North and Sahel Regions of Burkina Faso

Impact of Conflit on Children Vaccination: Evidence from Central North, North and Sahel Regions of Burkina Faso

Risk, emotion and responsibility: an analysis of the storylines used by vaccine hesitant mothers

Under processes of responsibilisation and individualisation in the ‘risk society’, as well as discourses of intensive motherhood, mothers are expected to make ‘good’ decisions regarding their children’s health. Consequently, decision-making concerning childhood vaccination becomes an emotionally challenging process, as mothers strive to minimise risk while simultaneously promoting and protecting health. Existing research shows that a substantial number of parents of young children have concerns regarding childhood vaccination. This article aims to examine how mothers who identify as vaccine hesitant dynamically construct risk, emotion, and responsibility when accounting for their decisions about childhood vaccination. Based on 15 in-depth interviews conducted in Belgium, this article reports the findings of a discourse analysis. For the latter, we draw on positioning theory and Lupton’s emotion-risk assemblage. The findings report three storylines that mothers discursively construct when discussing risk and responsibility in relation to childhood vaccination, namely a health promotion, a maternal protection and a critical healthcare consumer storyline. These storylines help to clarify the fluid and multidimensional nature of the mothers’ accounts of vaccine hesitancy. Furthermore, the findings provide empirical evidence for the use of the emotion-risk assemblage, as we find that vaccine hesitant mothers construct risk in relation to feelings of safety, control, empowerment, anxiety, fear, worry, intuition, vulnerability, being overwhelmed, pity and contempt. Overall, the findings demonstrate that when accounting for their decisions concerning childhood vaccination, hesitant mothers assume responsibilities within a context of social and gendered vulnerability, which affects their constructions of risk.

The effect of Plasmodium falciparum exposure and maternal anti-circumsporozoite protein antibodies on responses to RTS,S/AS01E vaccination in infants and children: an ancillary observational immunological study to a phase 3, randomised clinical trial

The RTS,S/AS01E malaria vaccine showed lower antibody response and protective efficacy in infants aged 6-12 weeks compared with children aged 5-17 months (for whom this vaccine is recommended). We aimed to study the effect of previous Plasmodium falciparum exposure on the antibody responses to RTS,S/AS01E vaccination in infants and children, and the mediating effect of baseline (including maternal) anti-circumsporozoite protein (CSP) antibodies. In this observational study, we included children and infants from six African countries (Burkina Faso, Gabon, Ghana, Kenya, Mozambique, and Tanzania) enrolled in the MAL067 immunology ancillary study of the RTS,S/AS01E phase 3 clinical trial from March 27, 2009, to Jan 21, 2011. We used comparator-vaccinated infants and children to identify antibody-based signatures of previous P falciparum exposure, which were later applied to RTS,S/AS01E-vaccinated infants and children. In these participants, we explored the relationship between vaccine antibody immunoglobulin G (IgG) responses measured by ELISA and pre-vaccination serological markers of malaria exposure by assessing the IgG levels against 1000 P falciparum antigens using partial proteome microarrays. We included 718 comparator-vaccinated infants (348 [48%]) and children (370 [52%]) and 606 RTS,S/AS01E-vaccinated infants (329 [54%]) and children (277 [46%]). Anti-CSP IgG responses to primary vaccination did not correlate with a baseline signature of previous exposure in children, suggesting that prior P falciparum exposure does not significantly affect antibody immunogenicity in children (Pearson's r=-0·02 [95% CI -0·13 to 0·10]). By contrast, high P falciparum exposure signature levels at the time of vaccination in infants, presumably driven by maternally transferred antibodies and declining within the initial 6-12 months of life, correlated with reduced RTS,S/AS01E responses (r=-0·17 [-0·27 to -0·06]). This negative correlation was stronger for anti-CSP IgG than for the exposure signature or any other more immunogenic blood stage P falciparum antigens (r=-0·42 [-0·50 to -0·33]), persisted after adjustment by baseline levels of the exposure signature (semi-partial correlation r=-0·44 [-0·55 to -0·33]), and involved antibodies to the central NANP region (r=-0·39 [-0·49 to -0·28]) but not the C-terminal region (r=0·02 [-0·10 to 0·15]) of CSP. The negative effect of maternal anti-CSP IgG in infants did not appear to be confounded by other malaria transmission-dependent variables. Interference between passive immunity and vaccine response is clinically significant and might affect the implementation of next-generation CSP-based vaccines for young infants and mothers as well as passive immunisation with human monoclonal antibodies. US National Institutes of Health, National Institute of Allergy and Infectious Diseases; PATH-Malaria Vaccine Initiative; Spanish Ministerio de Economía y Competitividad (Instituto de Salud Carlos III), European Regional Development Fund and European Social Fund; Fundación Ramón Areces; Spanish Ministry of Science and Innovation; and Generalitat de Catalunya (CERCA Program).

Immuno-persistence after the 4th and 5th dose of inactivated polio vaccines in school-aged children

ObjectiveThis study aimed to assess the long-term persistence of neutralising antibodies (nAb) titres and seroprotection proportions after the 4th and 5th doses of inactivated polio vaccine (IPV). MethodsSerum samples from 299 children in Hong Kong were collected and used to estimate the persistence of nAb titres and seroprotection proportions by neutralisation test. ResultsThe mean nAb titres against polioviruses type 1, 2 and 3 (PV1, PV2 and PV3) one month after receiving the 4th dose of IPV at 19 months of age were 2,068 (95% credible interval: 1,517 – 2,864), 4,705 (3,439 – 6,436) and 2,758 (1,894 – 4,086), but declined substantially in 4 years to 268 (222 – 325), 751 (630 – 900), and 411 (323 – 521), respectively. Administration of the 5th dose of IPV restored nAb titres among children aged 6-7 years, and the decline in nAb titres was slightly slower with the estimated mean titres of 355 (272 – 462), 538 (427 – 681), and 548 (378 – 786) against PV1, PV2, and PV3 at 4 years post the 5th dose. We estimated that the proportion of children who were seroprotected against PV1, PV2 and PV3 would drop below 90% at: (i) 8.2, 10.8, 8.7 years after the 4th dose; and (ii) 11.6, 11.2, 11.0 years after the 5th dose. ConclusionsThe results revealed the immuno-persistence after the 4th and 5th dose of IPV and highlighted the importance of completing immunization series to ensure high vaccination coverage, particularly among children in the developing countries affected by the COVID-19 pandemic.

The long-term cognitive and schooling effects of childhood vaccinations in China

The long-term cognitive and schooling effects of childhood vaccinations in China

SARS-CoV-2 Vaccination Coverage in Italian Children with Celiac Disease

Background: Celiac disease (CD) is the most common multisystemic autoimmune disorder affecting the pediatric population. However, little data is available regarding SARS-CoV-2 vaccination coverage in pediatric patients with CD. This study aims to evaluate the adherence to national recommendations for SARS-CoV-2 vaccination in children and adolescents with CD and its variation over time. Methods: We retrospectively analyzed medical charts and electronic registry records of SARS-CoV-2 vaccination of patients aged 0–19 years diagnosed with CD in a tertiary center. The vaccination coverage was evaluated according to age groups (young children, children, and adolescents), considering the patients’ eligibility for vaccination at different times. Results: Among the 172 patients enrolled, 44.8% received at least one dose of the SARS-CoV-2 vaccine, showing no significant differences compared to the Italian population of similar age. Vaccination coverage demonstrated a progressive reduction after an initial peak (up to 65.5% in December 2021) concomitant with a gradual extension of vaccinable eligibility and falling SARS-CoV-2 infections. Histological diagnosis and the presence of other associated autoimmune diseases were associated with higher levels of adherence to vaccination. Conclusions: Adherence to the SARS-CoV-2 vaccination in young Italian children with CD was very low, while it was better in adolescents and patients with other associated autoimmune diseases. Vaccine hesitancy remains a concern, particularly among those diagnosed using the biopsy-sparing approach. Hesitancy increased during the pandemic period, suggesting the need for ongoing efforts to improve adherence to SARS-CoV-2 vaccination recommendations.

KNOWLEDGE AND ATTITUDE OF URBAN AND RURAL MOTHER IN AL MUKALLA CITY ABOUT VACCINATION, 2023

Vaccination is a critical public health strategy for preventing infectious diseases in children, yet vaccine hesitancy remains a significant challenge, particularly among mothers who influence their children's health decisions. This study aims to evaluate the knowledge and attitudes of mothers in urban and rural areas of Al-Mukalla, Yemen, regarding childhood vaccinations. A total of 581 women with at least one child under five participated, with data collected on their knowledge, sources of information, and attitudes towards vaccination. Results indicated that urban mothers had a higher level of awareness regarding the importance of vaccination compared to their rural counterparts, with 76% of rural mothers lacking knowledge about its significance. Urban mothers primarily relied on media (71%) and doctors (56%) as information sources, while rural mothers depended more on societal channels. Moreover, urban mothers demonstrated a more positive attitude towards vaccination, in contrast to the skepticism observed among rural mothers, influenced by cultural beliefs and misinformation. The findings highlight a critical need for targeted educational interventions to address knowledge gaps and enhance vaccine uptake, particularly in rural communities, ultimately aiming to improve child health outcomes in the region.

The Effect of Parents' Fear of COVID-19 and Some Variables on Their Childhood Vaccination Attitudes According to the Health Belief Model: A Cross-Sectional Study

Objective: The study sought to explore the relationship of parents’ fear of COVID-19 and some variables with childhood vaccination attitudes according to the Health Belief Model during the COVID-19 pandemic. Methods: This research employed a descriptive – correlation design, with 263 participants consisting of parents with children aged 0-6 included in the study. An online survey was used to collect data. Results: The mean COVID-19 fear score of the participants was 19.71±6.46. As the COVID-19 fear score of the participants increased, their perceived benefit (β=.12; p

Increased Identification of Vaccines for Vaccine Safety Surveillance Through Linkage With the Minnesota Immunization Information Connection as of December 31, 2023.

The HealthPartners' Vaccine Safety Datalink (VSD) team maintains standardized files of vaccines from medical and pharmacy claims and electronic health records (established data sources) for safety surveillance. Since 2021, for selected vaccines, data from the Minnesota Immunization Information Connection (MIIC), Minnesota's immunization information system, have been added to the HealthPartners' VSD files. We examined how MIIC data have enhanced the identification of novel and routine vaccines. We describe the approach to incorporating MIIC data. We determined and compared the number and proportion of vaccines identified from established data sources with the additional capture of vaccine data identified from MIIC, in which age group and period of observation varied by vaccine. As of December 31, 2023, of 1 099 411 people in the HealthPartners' VSD cohort, 1 001 400 people (91%) were linked with an MIIC record. Across all data sources, for the full cohort, >2.7 million COVID-19 vaccine doses were recorded since 2020, >4000 mpox vaccine doses since 2022, >7.3 million influenza vaccine doses since 2004, >600 000 human papillomavirus (HPV) vaccine doses since 2006, and >1.1 million diphtheria and tetanus toxoids and acellular pertussis (DTaP) vaccine doses since 2004. For COVID-19 vaccines, about 30% of vaccine doses were exclusively captured from MIIC, with the remaining 70% from established data sources. For the mpox vaccine, about 42% were exclusively from MIIC. For influenza, HPV, and DTaP vaccines, about 20%, 14%, and 17%, respectively, were exclusively identified from MIIC. Incorporation of data from state immunization information systems into existing vaccine data files can enhance monitoring on the safety of novel vaccines administered outside traditional health care settings and can enhance data quality for routine childhood and adult vaccines.

Parents' Willingness to Vaccinate Their Children Aged From 6 Months to Under 5 Years With COVID-19 Vaccines.

Despite strides in vaccinating priority groups against COVID-19, children under 5 years in Vietnam are still under-immunized, emphasizing a significant gap in prioritization. This study aimed to assess parental willingness to vaccinate children aged 6 months to under 5 years against COVID-19 in Vietnam and identify influential factors affecting this willingness. Data were collected via a survey of 5960 parents/guardians between May and June 2022. Multinomial logistic regression was employed to analyze the impact of various factors on parents' willingness to vaccinate their children, alongside investigating reasons for reluctance or refusal and preferences for vaccine origins. Approximately 50.5%, 30.2%, and 19.3% of parents were willing, hesitant, and unwilling to vaccinate their children, respectively. Primary reasons for reluctance included concerns about vaccine safety, efficacy, and the severity of the pandemic. The most preferred vaccines originated in the United States. Factors significantly influencing willingness included parents' age, knowledge of COVID-19 and vaccines, residency, education, perception of information sufficiency, children's comorbidities, and family members' vaccination status. Promoting child vaccination habits can boost COVID-19 immunization rates. Targeting hesitancy among parents of children with comorbidities is crucial. Enhancing parental knowledge and leveraging fully vaccinated family members are effective strategies.

Evaluation of the immunization efficacy and adverse reactions of hepatitis B vaccination in children with thalassemia minor

ObjectiveTo assess the immunization efficacy and incidence of adverse reactions after hepatitis B vaccination in children with thalassemia based on data from real-world studies.MethodsA total of 625 children were recruited into this cross-sectional study. Subgroup analyses of different thalassemia types were performed using binary logistic regression, the factors affecting HBsAb levels were identified using multiple linear regression, and the dose-response relationship between the duration of immunization and seroconversion was explored using the restricted cubic spline (RCS) model to further assess the protective duration of the hepatitis B vaccine.ResultsHBsAb positivity in enrolled children was 87.3% in the thalassemia group and 81.4% in the control group. Multifactorial analysis revealed that the duration of immunization, age at completion of vaccination, and whether the first dose was delayed were significant factors influencing HBsAb levels in children (P < 0.05). The threshold for HBsAb positivity may be reached when the immunization duration reaches approximately 30 months. A subgroup analysis revealed that the HBsAb positivity rate was lower in children with β-thalassemia minor compared to those with α-thalassemia minor (P = 0.001, 95% CI: 0.097 ∼ 0.536). Adverse reactions after hepatitis B vaccination were dominated by general reactions, with a statistically significant difference in injection-site redness and swelling between the thalassemia and control groups (P < 0.05).ConclusionsThe immunization response to the hepatitis B vaccine in children with thalassemia minor was comparable to healthy children, with no abnormal adverse effects seen.

Assessing willingness to pay for children's COVID-19 vaccination among healthcare providers and users using a theory-based discrete choice experiment

Improving vaccine coverage among children is crucial to prevent the long-term consequences of COVID-19 infections and the emergence of resistant COVID-19 variants, especially in resource-scarce settings. This study determined factors influencing the willingness to take and pay for COVID-19 vaccine for children among Vietnamese healthcare professionals and the public. A Theory-Based discrete-choice experiment was focused on a different topic related to vaccines, including the COVID-19 vaccine for children, Monkeypox, the adult COVID-19 booster, the HIV vaccine, and a potential future pandemic. The recruitment period was from April to August 2022, and a total of 5700 Vietnamese individuals aged 16 and above from various regions of the country participated in the study. The data for the sub-study on the COVID-19 vaccination for children was completed by 891 of these participants. Most participants agreed on vaccination for all children. Among healthcare professionals it was 76.2% and 69.3% for the general population. Healthcare professionals were the main source of vaccine information (70.7%). Payment options of 50%, 100%, and full subsidy were the most popular. Concerns about vaccine characteristics were associated with lower acceptance among healthcare professionals and the general public. The burden of historical medical expenses negatively correlated with willingness to pay for vaccination, while service satisfaction positively correlated with willingness to pay. To develop an effective vaccination program among children in Vietnam, providing accurate information and satisfying vaccine services, primarily through knowledgeable and professional healthcare providers, can improve the willingness to vaccinate and pay for the COVID-19 vaccine.

Do Vaccines Cause Postural Orthostatic Tachycardia Syndrome? Review of Cases in the National Vaccine Injury Compensation Program

BackgroundThe National Childhood Vaccine Injury Act of 1986 created the National Vaccine Injury Compensation Program (VICP), a no-fault alternative to the traditional tort system. Since 1988, the total compensation paid exceeds $6 billion. Although postural orthostatic tachycardia syndrome (POTS) is a frequent reason for filing a claim, there has been no review of the process and validity of the legal outcomes given current medical information. The purpose of this study was to review vaccine-related POTS and assess the rationale behind decisions made by the court. MethodsWe identified 102 unique cases with POTS. All published reports were reviewed for petitioner's theories supporting vaccine-induced POTS, respondent's counterarguments, the final decision regarding compensation, and the rationale underlying these decisions. The primary goal was to determine which factors went into decisions regarding whether vaccines cause POTS. ResultsIn deciding the cases the Special Masters hearing the cases place a high reliance on expert witnesses for both the petitioners and respondents. Petitioners’ experts frequently implicated vaccines, primarily human papillomavirus vaccine, as causing POTS through autoimmunity induced by molecular mimicry. However, in none of the 102 cases was POTS considered to be directly caused by a vaccine. ConclusionsDespite the lack of epidemiologic or mechanistic evidence indicating that childhood vaccines covered by the VICP result in POTS, these cases continue to be adjudicated, at considerable cost to the government. Unless there is emerging scientific support for implicating vaccines in POTS it is time that the VICP stop considering these cases.

Hepatitis A vaccine immunogenicity among seronegative liver transplanted children.

The hepatitis A virus (HAV) vaccine is highly immunogenic in general, yet data on its use in liver-transplanted (LT) children is limited. This study aimed to determine the seroimmunity to HAV in all LT children, and the immunogenicity of an inactivated HAV vaccine in seronegative LT children at King Chulalongkorn Memorial Hospital. Seronegative LT children received the inactivated HAV vaccine at 0 and 6-8months with adverse events monitored for 3days post-immunization. The result reviewed that among 105 LT children, vaccination records were available for 81%, of which 7.1% and 16.5% with one and two doses of HAV vaccine were immunized before transplantation, respectively. Post-transplantation, 20.1% were seropositive for HAV, with 9.5% due to pre-transplant immunization. Eighty-three seronegative LT children (aged 7.25 ± 4.40years; 48.6% male) received two vaccine doses. The seropositive rate increased following the first and second doses and reached to 51.5%, and 92.9%, respectively (p < 0.001), with no serious adverse events reported. Age at vaccination and the interval from transplantation to vaccination were risk factors for non-responsiveness (p < 0.001). The study highlighted inadequate HAV vaccination coverage, leaving most LT children susceptible to infection. HAV vaccine proved highly immunogenic and safe, emphasizing the need for improved vaccination strategies before and after liver transplantation.Trial registration TCTR20220110001.

Sex differences in symptoms following the administration of BNT162b2 mRNA COVID-19 vaccine in children below 5 years of age in Germany (CoVacU5): a retrospective cohort study

BackgroundSex differences exist not only in the efficacy but also in adverse event rates of many vaccines. Here we compared the safety of BNT162b2 vaccine administered off-label in female and male children younger than 5 years in Germany.MethodsThis is a retrospective cohort study, in which we performed a post-hoc analysis of a dataset collected through an authentication-based survey of individuals having registered children aged 0-<5 years for vaccination against SARS-CoV-2 in six private practices and/or two lay person-initiated vaccination campaigns. We analyzed the safety profiles of the first 3 doses of 3–10 µg BNT162b2. Primary outcome was comparison in frequencies of 4 common post-vaccination symptom categories such as local, general, musculoskeletal symptoms and fever. Data were analyzed according to sex in bivariate analyses and regression models adjusting for age, weight, and dosage. Interaction between sex and BNT162b2 dosage was assessed. An active-comparator analysis was applied to compare post-vaccination symptoms after BNT162b2 versus non-SARS-CoV-2 vaccines.ResultsThe dataset for the present analysis consisted of 7801 participants including 3842 females (49%) and 3977 males (51%) with an age of 3 years (median, interquartile: 2 years). Among individuals receiving 3 µg BNT162b2, no sex differences were noted, but after a first dose of 5–10 µg BNT162b2, local injection-site symptoms were more prevalent in girls compared to boys. In logistic regression, female sex was associated with higher odds of local symptoms, odds ratio (OR) of 1.33 (95% confidence interval [CI]: 1.15–1.55, p < 0.05) and general symptoms with OR 1.21 (95% CI: 1.01–1.44, p < 0.05). Following non-BNT162b2 childhood vaccinations, female sex was associated with a lower odds of post-vaccination musculoskeletal symptoms (OR: 0.29, 95% CI: 0.11–0.82, p < 0.05). An active comparator analysis between BNT162b2 and non-SARS-CoV-2 vaccinations revealed that female sex positively influenced the association between BNT162b2 vaccine type and musculoskeletal symptoms.ConclusionsSex differences exist in post-vaccination symptoms after BNT162b2 administration even in young children. These are of importance for the conception of approval studies, for post-vaccination monitoring and for future vaccination strategies (German Clinical Trials Register ID: DRKS00028759).

Vaccination Coverage by Age 24 Months Among Children Born During 2017-2021 - U.S.-Affiliated Pacific Islands.

Childhood vaccination is one of the most successful public health interventions to improve life expectancy, decrease health care costs, and reduce the spread of preventable diseases. Using data from jurisdictional immunization information systems, vaccination coverage by age 24 months among children born during 2017-2021 in the U.S.-affiliated Pacific Islands was estimated for all vaccines included in jurisdictional programs. Progress toward the U.S. Healthy People 2030 and World Health Organization Immunization Agenda 2030 vaccination goals of ≥90% coverage by age 24 months with recommended vaccines was inconsistently met across jurisdictions. For example, coverage by age 24 months with ≥1 dose of measles, mumps, and rubella vaccine ranged from 68.2% to 91.6% by birth cohort in Federated States of Micronesia and from 87.4% to 96.6% in Palau; coverage with ≥4 doses of diphtheria and tetanus toxoids and acellular pertussis vaccine (DTaP) ranged from 39.6% to 60.6% in Federated States of Micronesia and from 73.4% to 85.4% in Palau. Coverage as of June 1, 2024, increased for all vaccines across all jurisdictions and birth cohorts, indicating catch-up vaccination after age 24 months. For example, coverage with ≥4 doses of DTaP by June 1, 2024, ranged from 74.0% to 84.4% in American Samoa by birth cohort and from 91.6% to 94.8% in Palau. This report is the first comprehensive analysis of trends in childhood vaccination coverage in the U.S.-affiliated Pacific Islands; data in this report can be used to determine where additional efforts are needed to assess reasons for delayed vaccination of children and strategies to mitigate vaccination delays, specific to each jurisdiction.